#字典
# dict_data={'k1':1,'k2':1}
# print(dict_data)
# dict_data={'k1':1,'k1':2}
# print(dict_data)
# v1={}
# v2=dict()
# v3=set()
# v4=tuple()
# print(v1,v2,type(v3),v4)
# info={
#     "姓名":"xiaofeng",
#     "年龄":20,
#     "性别":"男",
#     "爱好":["编程","乒乓球"]
# }
# print(info)
# user_list=[
#     {"name":"admin","pwd":"123456"},
#     {"name":"xiaofeng","pwd":"wwwwwww"}
# ]
# print(user_list)
# user_list={
#     "xiaofeng":"xiaofeng",
#     "admin":"123456"
# }
# user_name=input("请输入用户名：")
# user_pwd=input("请输入密码：")
# if user_list.get(user_name):
#     while  user_pwd!=user_list.get(user_name):
#         print("密码错误，请重新输入！")
#         user_pwd = input("请输入密码：")
#     else:
#         print("密码正确，登陆成功！")
# else:
#     print("对不起，该用户不存在！")
# info = {"age":12, "status":True, "name":"xiaofeng","email":"@xiaofeng.com"}
# data=info.keys()
# print(type(data))
# print(list(data))
# info = {"age":12, "status":True, "name":"xiaofeng","email":"@xiaofeng.com"}
# for i in info.keys():
#     print(i)
# info = {"age":12, "status":True, "name":"xiaofeng","email":"@xiaofeng.com"}
# for i in info.values():
#     print(i)
# info = {"age":12, "status":True, "name":"xiaofeng","email":"@xiaofeng.com"}
# for i in info.items():
#     print(i)
# info = {"age":12, "status":True, "name":"xiaofeng","email":"@xiaofeng.com"}
# for i in info.items():
#     print(i[0],i[1])
# info = {"age":12, "status":True, "name":"xiaofeng","email":"@xiaofeng.com"}
# for i,j in info.items():
#     print(i,j)
# info = {"age":12, "status":True, "name":"xiaofeng"}
# print(info)
# info.setdefault("h",180)
# print(info)
# info = {"age":12, "status":True, "name":"xiaofeng"}
# print(info)
# info.update({"name":'zhang'})
# print(info)
# info = {"age":12, "status":True, "name":"xiaofeng"}
# info.pop('age')
# print(info)
# info = {"age":12, "status":True, "name":"xiaofeng"}
# data=info.popitem()
# print(data)
# print(info)
# d1={"k1":1,"k3":3}
# print(len(d1))
# d1={"k1":1,"k3":3}
# print("k1" in d1)
# print("k1" in d1.keys())
# print(1 in d1.values())
# print(("k3",3) in d1.items())
# d1={"k1":1,"k3":3}
# print(d1["k1"])
# print(d1.get("k1"))
# d={"k1":3,"k2":2}
# d["k3"]=3 #添加
# print(d)
# d["k1"]=4 #通过键进行更新
# print(d)
# del d["k2"] #通过键进行删除
# print(d)
# info = {"age":12, "status":True, "name":"xiaofeng","email":"@xiaofeng.com"}
# for i in info.keys():
#     print(i)
# v = dict([("k1", "v1"), ["k2", "v2"]])
# print(v)
# info = { "age":12, "status":True, "name":"xiaofeng" }
# v1 = list(info)
# v2 = list(info.keys())
# #以上这两种是相同的结果 ['age', 'status', 'name']
# v3 = list(info.values())
# #[12, True, 'xiaofeng']
# v4 = list(info.items())
# #[('age', 12), ('status', True), ('name', 'xiaofeng')]
# print(int(3.14))
# data=int(3.141592628)
# print(round(data,3))
# print(0.1+0.2)
import decimal
a=decimal.Decimal("0.1")
b=decimal.Decimal("0.2")
print(a+b)